Heater control servo



Oct. 31, 1961 L. J. VANDERBERG 3,007,

HEATER CONTROL SERVO Filed Oct. 22, 1957 3 Sheets-Sheet 1 LJ. IANDERBERG INVENTOR.

Oct. 31, 1961 L. J. VANDERBERG 3,007,094

HEATER CONTROL SERVO Filed Oct. 22, 1957 3 Sheets-Sheet '2 "HHIIQJFA L.Jl44/VDERBER INVENTOR- Oct. 31, 1961 L. J. VANDERBERG 3,0 7,09

HEATER CONTROL SERVO Filed Oct. 22, 1957 3 Sheets-Sheet .5

LJ l/A NDERBERG IN V EN TOR.

A TTORNEYJ 3,007,094 HEATER CONTROL SERVO Lawrence J. Vanderberg, Ann Arbor, Mich., assignor to Ford Motor Company, Dearborn, Mich., a corporation ofDela'ware Filed Oct. 22, 1957, Ser. No. 691,631 2 Claims. (Cl. 31831) This invention pertains to servo systems and more particularly to a servo follow-up control system for the automaticselection and positioning of remote controllable functions.

An object of this invention is the provision of a servo follow-upmechanim'that controls a plurality of controllable devices.

A further objectis the provision of a servo system which is controlledby a single input.

An airnof this invention to provide servo control of the air conditioner functions in a motor car such as heating, ventilating, cooling and dehumidifying.

A further object is the provision in a motor car air conditioner system of a single control servo unit for the selection of a plurality of operating conditions,

These and other objects will become apparent from the reading of the following description in which:

FIGURE 1 is an exploded perspective view of the servo control unit;

FIGURE 2 is an electrical schematic of the commutator and a relay circuit suitable for operation of the invention;

FIGURE 3 is a sectional view of the commutator taken on line 3-3 of FIGURE 1;

FIGURE 4 is a plan view of the cam plate; and

FIGURE 5 is a sectional view taken on line 55 of FIGURE 1.

Referring to FIGURE 1, there is seen base 20 through which a plurality of cranks 21 are pivoted. A motor 50 drives worm gear 24. Cam plate 26 has a bushing 35 and is rotatably received on spindle 23. In the periphery of cam plate 26 are found gear teeth 27 which are driven by worm gear 24. As best seen in FIGURE 4, crank pins 22 are received within cam tracks 48 which provided movement of cranks 21 upon the motor rotation of cam plate 26.

Cam plate 26 carries a slotted brush holder 29 and brush 28 slidably received in holder 29. Brush 28 is a grounding brush which cooperates with commutator 30 in a maner that will be subsequently explained.

Commutator 30 is rotatably carried by commutator housing 38 as shown in FIGURE 5. Commutator 30 carries a stud 37 having a bearing 65 which is rotatably mounted below the housing 38 through bushing 64. A cable wheel 39 is carried by stud 37 above the housing and, therefore, rotates on bushing 64 with commutator 30. Control cable 41 engages cable wheel 39 and the excess lies within guide groove 40. Cover 45 is securable over the cable and cable wheel.

Terminal block 42 carries terminal 43, 44 and corresponding contacts 43', 44' which make contacts with electrical conducting strips 32, 31 on commutator 30.

Commutator 30 may be preferably a Bakelite disk with copper foil conducting strips on each side. Essentially, the strips take the form of a pair of arcuate copper foil conducting portions on each side of the disk. The top side, which appears in the exploded portion of FIGURE 1, supports an inner conducting arcuate portion 31 and an outer conducting arcuate portion 32. These portions are in electrical contact with terminals 33 and 34, respectively, and have as their purpose the conduction of power to the arcuate conducting portions on the bottom side of the disk. The means by which one of said connections is made through the disk is more clearly shown in FIG- United States Patent "ice 2 URE 3 as rivet 67 connecting portion 32 to portion 34. Portion 31 on the top is similarly connected to portion 33 on the bottom by rivet 68.

Transfer pin 47 is carried by commutator 30 and en gages diagonal slot 66 in brush 28. Pin 47, therefore, causes brush 28 to transfer its position in holder 29 as pin 47 passes through the brush. Brush 28 has electrical contactor portion 69 which is electrically grounded to the cam plate 26. The remainder a brush 28 may be a dielectric. Raised brush portion 70 forms a heel which rides upon the dielectric portion of commutator 30. The diagonal movement effected by transfer pin. 47, and diagonal slot 66 places the contactor portion 69 alternately, either on inside or outside arcuate portions 33,34. Isolated portion 36 provides an at rest or zero position for the brush and cam plate.

An electrical circuit for theoperation of this invention is shown in FIGURE 2 wherein the commutator is shown schematically. A split shunt reversible motor is 'shown generally at 50 having a' pair of fields 52, 53' and armature 51. A battery 47 supplies power for the circuit through a circuit breaker 54, Relay 55 has armature 56 and a pair of normally opened contacts 57 and 58. Also identical relay 59 has armature 60 and a pair of contacts 61 and 62. One of each pair of contacts is connected to a motor field and the remaining contact is connected to the armature of motor 50. Power is continuously supplied to the relay armatures 56, 60 and one side of the relay coils from the battery through lead 71. Therefore, one relay is effective to cause clockwise rotation of the motor and the other to cause counterclockwise rotation.

Brush 28 is shown superimposed over the commutator 30. Conducting segments 31 and 32 are shown by the broken lines schematically as their function is merely to supply power to segments 33 and 34 through relays 59 and 55, respectively. The pitch of the threads on the worm drive 24 and the connection of motor fields 52 and 53 are such that the brush is driven by the cam plate to recenter it on the isolation portion 36. Brush contact on segment 33 as shown will cause brush rotation in the direction of the arrow to cause slot 66 to pass over the transfer pin 47 and recenter the brush on the isolation segment 36.

In the operation of my invention the control cable 41 is axially positioned to select a desired movement of the controls operated by cranks 21. The cable may conveniently be positioned by a rotating indicator dial or a sliding control arm with a plurality of stations indicated thereon corresponding to the functions to be selected. The five crank pins shown driven as they are by cam plate 26 may control bowden wire cables to heater, fresh air dampers, defroster vents, heater temperature controls, and left and right fresh air vents as examples.

The amount of rotation of the cam is controlled by the amount of angular displacement of the commutator which turns with the cable wheel. The displacement of the commutator to a station or position corresponding to the function desired to be selected by the cam-driven cranks causes one of the relays 55, 59 to be actuated depending on whether the brush 28 is in contact with segment 33 or 34. The closing of a relay supplies power to the motor to cause the cam plate to follow up the commutator movement until the relay circuit is broken by brush 28 centering on isolation segment 36.

It is, therefore, seen that a multitude of functions may be controlled by a single control cable. Further, the overlap design of the clockwise and counterclockwise conducting portions permits up to 330 cam plate rotation in either direction thereby affording considerable latitude in the design of the cam slopes to provide the desired movement.

What is claimed is:

1. An electrical control mechanism comprising a commutator having two conducting tracks separated by a non-conducting portion, a rotatable output member, means for angularly positioning said commutator, a slidable brush carried by said output member engaging one of said conducting tracks at one time, a shifting means mounted on said commutator to slide said brush radially from one conducting track to the other conducting track upon the angular positioning of said commutator, a prime mover in driving relationship to said output member, and means energizing said prime mover in one direction by engagement of said brush with one of said tracks and in the other direction by engagement of said brush With the other of said tracks.

2. An electrical control mechanism comprising a rotatable output member, a reversible drive motor in driving relationship to said output member, a commutator having an inner and an outer circumferential conducting track separated bya non-conducting portion and having a dielectric portion forming a gap in the inner and outer circumferential conducting tracks, a means for angularly positioning said commutator, a pin extending from said 4 commutator, a slidable brush carried by said output member and being adapted to be shifted radially by said pin from said dielectric portion to engage one of said oonducting tracks of said commutator upon the selectively angular positioning of said commutator, and a circuit means including said brush and said commutator for energizing said reversible motor in one direction when said brush is in engagement with the inner conducting track and for energizing said motor in the opposite direction when said brush is in engagement with the outer conducting track, said motor when energized rotating said output member until said sliding brush is in contact with said dielectric portion.

References Cited in the file of this patent UNITED STATES PATENTS 1,798,592 Davis Mar. '31, 1931 1,917,507 Demkier et al July 11, 1933 2,413,137 Dederick Dec. 24, 1946 2,420,026 Yardeny May 6, 1947 2,428,403 Yardeny Oct. 7, 1947 2,496,575 Bousky Feb. 7, 1950 2,530,750 Yardney Nov. 21. 1950 

